MEDULLA OBLONGATA
MEGESTROL
the adrenal medulla is the central
region of an
adrenal gland
.
The term
“medulla” is also sometimes used to
refer to the
medulla oblongata
.
medulla oblongata
Also known as the
medulla
, the lowest part of the
brain-
stem
. The medulla oblongata lies in the
skull just above the spinal cord.
MEDULLA OBLONGATA
Thalamus
Midbrain
Pons
Brainstem
Medulla
oblongata
Spinal
cord
LOCATION
medulloblastoma
A type of cancerous
brain tumour
that occurs mainly in chil-
dren. The tumour usually arises from the
cerebellum
, which is concerned with
posture, balance, and coordination. It
grows rapidly and may spread to other
parts of the brain and to the
spinal cord
.
A morning headache, repeated vomiting,
and a clumsy gait develop. There are
also frequent falls. The tumour is diag-
nosed by
CT scanning
or
MRI
and often
responds to
radiotherapy
. Surgery and
anticancer drugs
may also be needed.
mefenamic acid
A
nonsteroidal anti-
inflammatory drug
used to relieve pain
and inflammation. Possible adverse ef-
fects are typical for this group of drugs.
mefloquine
A drug used for prevention
and treatment of
malaria
in parts of the
world where the parasite that causes it
is resistant to
chloroquine
. Mefloquine is
one of the preferred treatments for fal-
ciparum malaria. Side effects include
nausea, vomiting, and diarrhoea. Rarely,
there may be
panic attacks
,
halluci-
nations
,
and
psychosis
.
mega-
A prefix meaning very large, as in
megacolon
, a condition in which the
colon is greatly enlarged. The prefix
megalo- has the same meaning.
megacolon
A gross distension (enlarge-
ment) of the
colon
, usually accompanied
by severe, chronic
constipation.
In children, the main causes of mega-
colon are
anal fissures, Hirschsprung's
disease
, and psychological factors that
may have arisen during toilet-training.
In elderly people, causes include the
long-term use of strong
laxative drugs.
People suffering from chronic
depression
or
schizophrenia
often have megacolon.
Other, rarer causes include
hypothy-
roidism
,
spinal injury
, and drugs such as
morphine
and
codeine
.
Megacolon causes constipation and
abdominal bloating. Associated loss of
appetite may lead to weight loss. Diar-
rhoea may result if semi-liquid faeces
leak around the obstructing hard faeces.
Diagnosis is made by
proctoscopy
,
barium X-ray examination
, and tests of
bowel muscle function. If Hirschsprung's
disease is suspected,
biopsy
of the large
intestine may be performed. Impacted
faeces are often removed using
enemas
.
In severe cases, the faeces must be
removed manually.
megaloblastic anaemia
See
anaemia,
megaloblastic
.
megalomania
An exaggerated sense of
one's own importance or ability that
often occurs in
mania
. Megalomania
may take the form of a
delusion
of
grandeur, or of a desire to organize
activities that are expensive, large in
scale, and involve many people.
-megaly
A suffix meaning enlargement,
as in
acromegaly
, a condition in which
there is enlargement of the skull, jaw,
hands, and feet due to excess produc-
tion of
growth hormone.
megestrol
A
progestogen drug
used to
treat certain types of
breast cancer
and
uterine cancer (see
uterus, cancer
of). It
may be prescribed when a tumour can-
not be removed by surgery, if a tumour
has recurred after surgery, or when
other
anticancer drugs
or
radiotherapy
prove ineffective.
Possible adverse effects of megestrol
include swollen ankles, weight gain,
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